1. Field of the Invention
The invention relates to a water container, more particularly to a container for storing and supplying water under pressure.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional water container 10 is shown to comprise complementary upper and lower container parts 11, 12, a retaining ring 13 and a water and air impermeable flexible partition member 14. The upper and lower container parts 11, 12 are made of plastic. The upper container part 11 opens downwardly, and has a bottom rim 111. The lower container part 12 opens upwardly, and has a top rim 121. The upper container part 11 has a top end formed with a water inlet 112 that is adapted to be connected to a water valve (not shown). The lower container part 12 has a bottom end formed with an air inlet 122 that is adapted to be connected to an air valve (not shown). The retaining ring 13, such as an annular washer, is formed with a radial outward peripheral flange 131. The partition member 14 is disposed in the upper container part 11, and is configured to line an inner wall surface of the same. The partition member 14 is formed with a peripheral lip 141.
During assembly, the flange 131 and the lip 141 are received in an annular groove 113 that is formed in the bottom rim 111 of the upper container part 11. The upper container part 11 is then disposed on top of the lower container part 12, and the bottom and top rims 111, 121 are bonded sealingly to each other via known high frequency welding techniques such that the flange 131 and the lip 141 are clamped tightly between the rims 111, 121. At this time, the partition member 14 cooperates with the upper container part 11 to form a volume variable water chamber (A), and further cooperates with the lower container part 12 to form a volume variable air chamber (B) that is sealed off from the water chamber (A).
In use, water is introduced into the water chamber (A) via the water inlet 112. Pressurized gas is introduced into the air chamber (B) via the air inlet 122. The partition member 14 deforms due to the weight of the water in the water chamber (A), thereby compressing the gas in the air chamber (B). Thus, when water pressure at the water inlet 112 drops, the compressed gas in the air chamber (B) forces the partition member 14 upwardly so that water can be released from the water chamber (A) under pressure.
In the aforesaid conventional water container 10, the retaining ring 13 is essential to maintain tight contact among the partition member 14 and the upper and lower container parts 11, 12. Without the retaining ring 13, leakage of air and/or water can easily occur at the joint of the partition member 14 and the upper and lower container parts 11, 12. However, due to the presence of the retaining ring 13, the production cost of the conventional water container 10 is accordingly increased. Moreover, even with the presence of the retaining ring 13, it is observed that leakage of air and/or water can still occur due to the lack of a facility to ensure tight contact between the retaining ring 13 and the partition member 14. Furthermore, because the lip 141 is relatively small in size, the securing effect provided thereto is relatively weak, thereby resulting in an increased risk of air and/or water leakage.